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fuel surge tank for EJ Swap


Pooparu
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For all the people who have done the EJ swap how many of you added a fuel surge tank?

 

I had heard that with when you swap an EJ22 into an EA81 vehicle you'll get a problem with the car stalling when the fuel is low 'cause it sucks air into the lines and causes the vehicle to stall.

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It's not specifically an EJ swap problem. My SPFI Brat does it as well. It's the fuel injection system - it must remain pressurized and the tank has no baffles to prevent sloshing.

 

I found some plans for a surge tank searching the internet a while back. The guy made one from a tap water filter housing from home depot. I was thinking along those lines but I'll probably wait till I find something at work that will do the trick.

 

GD

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It's not specifically an EJ swap problem. My SPFI Brat does it as well. It's the fuel injection system - it must remain pressurized and the tank has no baffles to prevent sloshing.

 

I found some plans for a surge tank searching the internet a while back. The guy made one from a tap water filter housing from home depot. I was thinking along those lines but I'll probably wait till I find something at work that will do the trick.

 

GD

 

so do I need a fuel pump before and after the surge tank? I found one with a fuel pump inside the surge tank.

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There is no fuel surge tank on the legacies. There is a baffle in the fuel tank where the pump sock goes, but that's it. Is that what you're talking about?

 

all subarus with fuel injection have the baffles (I don't remember if carbed EA82s do or not). but EA81s don't.....

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I have a ej22 swapped '86 GL that was originally carbed. I get some stuttering sometimes, and I've pretty much narrowed it down to a fuel issue. I've been wondering if a surge tank would help, but I'm not sure how to go aobut setting one up either.. like where to put the fuel pumps, etc...

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I made mine from a 32oz RC airplane fueltank. Cut one end just big enough to fit over the pump and pickup make a few holes and zip tie it to the strut that holds the pump. Then run the return line directly into the tank. Finally add a couple small holes near the halfway point to help it fill even more.

 

Works well enough for the investment.....and saves money for more :drunk: ....which leads to more ideas.....:-\

 

Jay Storm

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I made mine from a 32oz RC airplane fueltank. Cut one end just big enough to fit over the pump and pickup make a few holes and zip tie it to the strut that holds the pump. Then run the return line directly into the tank. Finally add a couple small holes near the halfway point to help it fill even more.

 

Works well enough for the investment.....and saves money for more :drunk: ....which leads to more ideas.....:-\

 

Jay Storm

 

did you place it before or after the fuel pump?

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I don't think he's talking about the same thing. Sounds like he's refering to something with an in-tank pump vs. the EA series remote tank mounting.

 

You would need a pump (carb pump will do) that fills a sealed surge tank (tall and skinny) with a return line at the top to expell excess fuel back to the tank. Then the fuel injection pump feeds from near the bottom on the side of the surge tank cylinder. There should be inline filers for the surge tank pump, and another filter for the FI pump. The injection pump return line then needs to return fuel back to near the top of the surge tank. If it returned it to the tank it would quickly empty the surge tank as the flow is very high.

 

GD

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I don't think he's talking about the same thing. Sounds like he's refering to something with an in-tank pump vs. the EA series remote tank mounting.

 

You would need a pump (carb pump will do) that fills a sealed surge tank (tall and skinny) with a return line at the top to expell excess fuel back to the tank. Then the fuel injection pump feeds from near the bottom on the side of the surge tank cylinder. There should be inline filers for the surge tank pump, and another filter for the FI pump. The injection pump return line then needs to return fuel back to near the top of the surge tank. If it returned it to the tank it would quickly empty the surge tank as the flow is very high.

 

GD

 

Oh, that's just what I needed to know. Thanks for the information.

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this is what i did it fits the stock EJ fuel pump and sending unit that i shortened to make the tank smaller , so the stock carb. pump fills little tank and returns when full to the big tank and the little tank runs the engine the engine returns back to the little box if that makes sense ? if i shut off the carb. pump it will run for like a 1/2 hour on just the small tank if im easy on it :lol:

 

halloween_party_023.jpg

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I wish I could buy something like that. (interested in making some money?);)

 

sure but its not the money its the time and thats what i dont have much of , it would be easy for me to make a box to your size you need and i could weld the fitting pads and mount brackets , but its the cutting sizeing and drilling and taping that takes the most time if you were willing to do that it would be cheaper , 100$ is a nice round number :), if you really wont one let me know exactly the size and ware you want the hose fittings and brackets , a simple drawing would be best , but i cant promise a time i would have it finished i would have to do it in my spare time .

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sure but its not the money its the time and thats what i dont have much of , it would be easy for me to make a box to your size you need and i could weld the fitting pads and mount brackets , but its the cutting sizeing and drilling and taping that takes the most time if you were willing to do that it would be cheaper , 100$ is a nice round number :), if you really wont one let me know exactly the size and ware you want the hose fittings and brackets , a simple drawing would be best , but i cant promise a time i would have it finished i would have to do it in my spare time .

 

I'll get under my car and try to figure out where I want the thing and come up with some kind of drawing that I can scan in and email to you.

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What about using an RCI fuel cell like the one that was on my Datsun 521? I think they're $100-$150 new, and have foam inside to prevent sloshing.

 

Lets see.....

 

1. Expensive. (you need more than just the tank too).

2. Small.

3. Smelly (inside the cabin on a hatchback).

4. Inconveient - takes up cargo space, have to open the hatch to fill it, etc.

 

Not to mention there's just no need. You can make a surge tank from some parts out of home depot for like $30.

 

I WILL be using a fuel cell eventually on my Hatch - but it's a totally different animal. The only real good reason is to prevent stuff from smacking into the tank off-road - but unless you are going with a t-case lift you won't be getting into situations where that's really a problem. Plus in my case I'm removing the rear seats entirely for extra space and I'm going to sink the floor down where the existing tank is located.... there's a time and a place for fuel cell's, but not on a rig like his.

 

GD

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Any more thoughts on this?

 

Since EJ'ing my wagon I've had some weird issues, all come back to fuel starvation/over pressurizing the tank. I'm very close to setting up a surge tank system using the one rguyver linked to.

 

My plans are for the stock ea82 carb pump to be in the stock location. Pump it up one of the top fittings on the 1 gallon tank. Using the factory Y fitting to have the stock tank return hooked up. Then I'll use the aftermarket bosch pump I have to pump out of the 1 gal to the motor. The motor will return to the second fitting on the top.

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this should work good as a surge tank and i cant build it for that price it would take me a day to fab up the parts and 30$ in fittings . but you would have to use an external fuel pump to run the engine . http://store.summitracing.com/partdetail.asp?autofilter=1∂=RCI%2D2010A&N=700+400379+4294920243+4294903853+115&autoview=sku

 

So what would my total cost be?

 

I'm thinking that I might just mount it where the jack was located on the inner passenger side fender. Then mount the HP pump next to it.

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